Once there lived a Brahmin with his wife named Shandili, in an outer area of a city. They were very poor but they live happily together.
One day the Brahmin said to his wife, “There is a special day tomorrow, there is a festival. So it will be a good time for alms. I shall visit the city tomorrow and I am sure that I shall collect a lot of things for us which will last for many days.” He continued himself, “You must invite a Brahmin tomorrow and take him food and clothes. It is an auspicious day so it will be a good act.”
After hearing this, his wife said to him, “How can you say all this? We are already very poor, we cannot invite any Brahmin. We cannot afford good food and good clothes for giving a Brahmin.”  But the Brahmin began to explained her, “My dear wife, whatever we have we must share at least half of it with a needy person. It is a good deed.”
After much of conversation the Brahmini agreed to him. She said, “I have only some sesame seeds to offer a Brahmin. I will clean it properly and remove their husks, and cook a delicious dish for a Brahmin."  The Brahmin agreed.
The next morning the Brahmin went to the city according to the plan. When he gone away, his wife began to clean the sesame seeds and removed their husks. After that she put the seeds in the sun and began to start his household work. After sometime when she was busy with her household activities, a dog came there and contaminated the seeds. When she saw the dog she immediately ran towards the dog and the dog went away. 
She became very sad and thought, “Fate has ruined all my efforts. But I have nothing else except these sesame seeds. So I will try to play a trick with my neighbour. When I will offer these cleaned, un-husked seeds in exchange of some husked sesame seeds, she will not suspect to me and will definitely accept the offer.”
Then she went to her neighbour and offered an exchange. The lady was attracted towards the offer. She thought that it takes much time to clean these husked seeds. The offer is quite good. So she agreed to accept her exchange offer. As she take out some husked sesame seeds to give the Brahmini and began to give her, her son came out. He said to his mother, “MAA! Who would exchange cleaned sesame seeds with uncleaned ones? There must be some reason that she offers such exchange offer. There may be a trick behind all this. Please do not accept the exchange." 

When the lady heard her son’s advice, she began to thought and at last refused for the offer. Then the Shandili realized that she had failed to play the trick on her neighbour, and then she returned home.

The wise indeed say:

When someone offers you something that is too good to be true, don't be accepted it immediately – Think and analyse it first.